Power transmission



u y 1945- D. A; WALLACE ETAL 2,404,330 POWER TRANSMISSION Filed Sept. 2, 1941 5 Sheets-Sheet 1 I NVENTOR5M Fat id -fl I I 42214 2,

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- ATTORNEYS.

POWER TRANSMISSION 5 Sheets-Sheet 2 Filed Sept. 2, 1941 INVENTORS. 2%

ATTORNEYs.

5 Sheets-sheaf. 5

D. A. WALLACE ETAL POWER TRANSMISSION Filed se t z, 1941 July 16, 1946.

, 3&9 B Ju 52:24, PJZUM ATTO R N E Y5.

July 16, 1946.

Filed Sept. 2, 1941 -D. A. WALLACE ETAL POWER TRANSMISSION 5 Sheets-Sheet 4 ATTORN EYS.

y D. A. WALLACE ETAL v Q POWER TRANSMISSION Filed Sept. 2, 1941 5 Sheets-Sheet 5 M7 AM ATTORNEYS.

Patented July 16, 1946 r UNITED TATES PATENT OFFICE David A. Wallace and Edward 0. Lee, Detroit,

Mich., assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application September 2, 1941, Serial No. 409,210

11 Claims. (01. 192-35) 1 2 This invention relates to improvements in mechanism, the positions of the parts correspondpower transmissions, particularly in the shifting ing to Fig. 6. l; V mechanism for such transmissions. Fig. 8 is a sectional view of the Fig.7 mecha- It is the main object of the invention to pronism with the clutchfully released. vide a simple and economically manufactured l i Fig. 9 is a sectional view of the Fig.6 mechapower shift apparatus for conventional types of nism, the parts being shown in second'speed povehicle change speed transmissions. sition with the clutchreleased. During recent years variou forms of automatic Fig. 10 is a sectional view of the valve op and semi-automatic power transmissions have ating mechanismfthe positions of the parts';corcome into vogue for motor vehicles. For the most 9 responding to Fig. 9 with the clutch engaged; and

part these transmissions have been costly to mang- 11 i a ectio al Vie of t e ve ope at ufacture and have required considerable reormechanism with the. clutch released to normal ganization of other parts of the vehicle besides release position, thetransmission parts being in requiring the learning of a somewhat different high speed or direct drive'position; I

driving technique on the part of. the driver. .1? Referring to Figs. 1 to 5, it. may be seen'that 'The power shifting apparatus disclosed and we have illustrated our invention as applied to a claimed hereinis adapted for ready attachment motor vehicle havingan'en a releasable to vehicles equipped with conventional manually friction clutch B and a manually shiftable trans-,- operable change speed transmissions either as a si The clutch B may be of nt factory installation or as a service accessory. meroially' available type and 1's releasable by The regular engine oil pressure system is-used to means of a release mechanism 50, the fork--5l supply operating oil pressure and the transmisthereof being connected to the clutch pedal. 52 sion-control is not disturbed except thatshifting y y Suitable lin age suoh'as, for ex m e t of gears between second and high speed ratio is illustrated in Auten Patent No; 2,232,302, issued p o med y power means in response to ordi- February 18, 1941. i i

nary operation of the clutch pedal. I The clutch is enclosed in a housing 53: mounted A further object'therefor is to provide a power in the block ofthe engine A and a housing or shifting apparatus operable to shift the trans- Casing 54 for e transmission 0 iss e d mission gears in response to operation of the vethe real end t A h b w y-co hicle clutch pedal. 7 nects the clutch B with the transmission: 1 This Other advantages and objects will become apshaft has a drive pinion 56 formed thereon which parent from the following description. In the meshes with a gear 51,01 a countershaft cluster drawings accompanying Said description, 58 carried by a countershaft 59; The cluster ini 1 is a partial side elevation of an autodudes also a'geal' 60 disposed in mesh. th the mobile power plant and change speed transmissecond speed drive speed 62 ign embgdying the present invention i and. a reverse gear 63. A- shiftable gear. splined Fig 2 is a rear end elevation f the on the mainshaft 65 is adapted to be shifted into mission I i mesh with the gear 62 to provide low. speed-ratio Fig. 3 is a combined side elevation and sectional view in an enlarged scale of the transmission showingthe -control mechanism thereof, Own i a gear 63.

bemg taken as mdlcated by me A shiftable clutch sleeve 61 issplined on the 0 reverse drive; the gear 68 being carried ,byits aft in permanent mesh; withthe drive, or with a reverse'idler gear J66 to provide 33 in Fig.2. V

Fi 4 is a sectional view of the transmission 8, 1 52 1 5 p t g; a mph the showing the gears. I c u c ee of pinion 0r -d1rec drive, or V i .1 with the clutch teeth 69 of gear 6| for second f 5 plan. new of the tranm1ss1m speed ratio drive. Suitable blocker synchronizers casing being partially cut away to illustrate de- 70 and H are provided prevent clashing of tails of the shift mechanism. teeth as is common in the am I 6 is an enlarged sectional View of the 50: The clutch sleeve Gland gearli l lare-shiftable dmuuc shifting mechanism, the parts being bya manually operated remoteshiftmechanism shown in neutral position with th clutch enwhich comprises aytrunnion member lZrockably.

gagfact l e i carried'by a rockshaft 13 by meansiof aipin l l. 7 1s a sectional view taken along the line The: rockshaft'is rotatably -carried by a casing fi' e f 2 and showin the valve operating [1 cover and extends outwardly therefrom; an

7 1 piston rod I08.

operating lever I6 being fixed on its outer end. A shift finger TI carried by. the trunnion I2 is adapted to selectively engage slots I8, I formed in shift yokes 80, 8| respectively.

; The shift yoke 80 is carried by a rail 82 and has an integral fork portion which engages the s t llar po tion 83 f the clutch sleeve 6].-

The yoke 8| likewise has a fork portion which engages a shift collar 84 formed on the lowreverse gear 6|. Both yokes are slidable on a rod85 and the rails 82, 83 are operatively engaged by the usual detent mechanism 86 and interlock pin 81.

The finger 'I'! is biased by a spring (not shown) into engagement with the yoke 0 at. all times A selector lever 88 carried by a shaft a e is adapted for actuation by a lever 90 (Fig. to. rock thetrunnion 12 on the pin 14 to disenga e. the

' arates a pair of chambers H1, H8;

A stem I I9 is slidable within the plunger I I5. This stem has an enlarged central portion I which snugly and slidably fits within a bore formed in the plunger for receiving the same.

The valve stem I I9 carries apair of coil springs IZI, I22 which are adapted to be compressed between washers I23 suitably positioned in the stem as will presently appear. end of the stem is a cOllar I24 which is engaged by the bifurcated lower end of the valve operatir g arm H0. The latter is slidable on the collar I24 within the limits permitted by the shoulders thereon as will be clear from the drawing.

Disposed outwardly adjacent the valve in the casing I03 is an interlocking mechanism which comprises a plunger I25 slidable in a bore I20.

finger 11 from the slot 18 in yoke 80. and engage I carried by the vehicle steering column which includes a Bowden cable 92 andshift links 93, 94

connected by bell crank 95. The arrangement is such that the driver operable shift "lever (not shown) may be swung about its mounting in two parallel paths of movement; the lower path controlling the yoke 8| and'the upper path controlling theyoke 80.

Most motor vehicle manufacturers offer an overdrive transmission as optional 1 equipment and on those models not equipped withoverdrive an extension housing is fastened to the rear end .of' the-trans'm-ision casing in the space which would ordinarily be occupied by the overdrive gearing and casing. We have modified this extension housing and adapted it for. housing the operating parts of our hydraulic shifting'mechanism, but it is desired to point out that our invention is not limited in its application to this precise construction.

As will be seen from Figs. 1-5, a housing I00 is seeured'by bolts IOI to the casing 54. The housling I00, is'hollow, the mainshaft 65 extending therethrough, and has means formed thereon.

indicated by numeral I02, for mounting the usual lpropeller shaft brake (not shown). Formed on the housing I00 is a casing I03 which houses the fluid pressure motor and valve mechanism.

The fluid pressure motor comprises a. cylin- 'der l0=4 closed at its forward end by a head I05 and at its rear endby a head I03. Slidable with in the cylinder is a piston I01 which carries a The latter extends forwardly 60 1 into casing 54 where it is connected by means of a pin I09 with the second-high rail 82, and rearwardly of thehead I06 where a valve operating arm I I0 is mounted thereon. A suitable packing ygland II I is provided adjacent the forward cylinder head for sealing the cylinder.

The cylinder I04 is ported at H2 and H3 for 'ported'sleeve' I I4 having a shrunk fit in the casing The plunger has a ramped rear portion I2'I which engages a plunger I28. The latter has an internal bore in which is carried a detent plunger I29 and a spring I30. The plunger I29 is 'permitted'to move inwardly of the bore of plunger I28 against the spring I30 only when the plunger I25 is in the Fig. 9 position.- When theplunger I25 is moved rearwardly of its bore to the position illustrated in Fig. 10, plunger I28 is thrust into its bore compressing spring I30 which prevents f yielding of the detent plunger I29. Thislocks the valve plunger II5 against movement the I03 below the cylinder I04. -Slidably disposed within the sleeve is a plunger H5 having a cen trally positioned enlarged portion II'6 which sep plunger I29 being always engaged withjone of the locking grooves I3I formed in the valve plunger.

Plunger I25 has a forward reduced portion-I32 which is fastened by a pin I 33 to a rod I 34. The

latter is inturn-operably connected by a link I35 and a pin I36 with the clutch throwoutfork 5| j (Figs. 3 and 5). The arrangement is such that depression of the pedal 52 to effect release of clutch B will also efiect rearward movement of plunger I 25 in bore I26 thereby to lock valve plunger I I5.

A collar I '31 is slidably disposed in the bore I25. This collar is loose on the reduced portion I32 of the plunger I25 but snugly engages the bore. IA detent I38 of the well known spring pressed ball type is adapted to engage one or the other of a pair of grooves I39 formed in the collar as will be further explained herein. I I

The casing I03 has an inlet I40 which is connected by a pipe MI with the engine oil pump I42. A similar pipe I43 connects the casing outlet or vent port I54 with the crankcase as illustrated in Fig. 1.

.' The valve sleeve H4 is provided with a passage I lfiwhich connects with the cylinder port I I2 and with a port I475 which opens into the sidewall of r the cylinder as shown in Fig. 6. The vent pas sage I44 connects with a passage I 41 which is dis posed longitudinally of the cylinder and connects with valve sleeveports I48 andI 49. A drain passage I50 opens into the passage I41 for draining the interior of the valve.

The enlarged portion IIB of the valve stem II5 separates two annular valve chambers III, IIB carried by the stem which chambers are adapted to selectively connect certain of the ports and passages as will presently be made clear.

The inlet port I40 is connected with the control valve by passages I53, I54, I55 and I50 When the plunger I25 is moved rearwardly sufl'iciently' to uncover passages I53 and I54, but not sufficiently to move the collar I31. This condition of the plunger is shown in Fig. 11.

Fluid flowing into the valve is blocked by the h enlarged portion H3 of the stem II5 when the Fixed in the rear latter is in neutral position (Figs. 6, 7, and 8). When the stem is in second speed ratio position (Figs. 9 and and the plunger I25 is in clutch released position as in Fig. 11, fluid under pressure flows into valve chamber II1 and thence through passage I5I and cylinder port 3 into cylinder I04 in rear of piston I01 whereupon the piston I01 is thrust forwardly to shift the sleeve 61 to direct drive position. At the same time the forward portion of the cylinder is vented through port II2, passage I45, port I46, chamber IIB, port I49 and port I44, vent port I48 being covered by the forward head of the valve stem.

Similarly when the stem H5 is thrust forwardly to high or direct drive position (not illustrated) vent port I49 is covered by the rear head of the stem and chamber H8 is opened to pressure port I56, which is thus connected to the cylinder by way of passage I45. At the same time the rear end of the cylinder is vented through passage I5I, chamber .I I1, port I48 and passage I41.

The operation of the apparatus is as follows: It will be noted that the power actuated shift mechanism is effective for shifting the sleeve 61 only, the low-reverse drive gear 64 being hifted manually in conventional manner.

Let it be assumed that the vehicle is at rest with engine A running and the regular manually operable remote shift control lever in neutral position, the clutch pedal 52 being in clutch engaged position as illustrated in Fig. 1. In order to drive the vehicle forwardly the driver depresses the clutch pedal 52, to the full extent of its travel which action disengages the clutch B and through the action of the link I35 the plunger I25 is thrust rearwardly to the full extent of its travel as illustrated in Fig. 8. Rearward movement of the rod I34 to the position shown in Fig. 8 effects movement of the collar I31 in a rearward direction sufiiciently to close the inlet passage I53 thereby preventing the pressure fluid from entereffective, the clutch 52 is depressed only enough to release the drive through clutch B when shifting by the power means and this movement of the clutch pedal is not sufficient to displace the collar I31 which is retained in the position shown in Fig. 7 by the detent mechanism I 38 at all times except when the transmission is shifted manually, under which conditions the clutch pedal is depressed to the full extent of its travel to thereby displace the collar I31 and prevent the pressure fluid from entering the main control valve.

While the clutch pedal 52 is depressed to the full'extent of its travel as aforesaid, the transmission remote shift mechanism may be manipulated to shift the gear 64 into mesh with the countershaft cluster gear 62 thereby to set the transmission mechanism for forward travel in low speed ratio upon engagement of clutch B. Inasmuch as the position of gear 64 is controlled by rail 83 the piston I01 of the shifting motor is not disturbed. Release of clutch pedal 52 and depression of the accelerator pedal I52 will now cause the vehicle to be driven forwardly in low speed ratio and when the vehicle has been accelerated to desired speed, shift to second speed ratio may be accomplished manually by depression of the clutch pedal 52 to the full extent of its travel and manipulation of theremote shift mechanism to shift the sleeve 61 rearwardly intomesh with clutch teeth 69. This action effects rearward travel of the piston. I01 to the position shown in Fig. 9, which movement of the piston is freely permitted because both ends of the cylinder I04 are vented, the stem I I5 of the main control valve being locked in neutral position by plunger I29 as illustrated in Fig. 8.

Movement of the piston rod I08 rearwardly Release of the clutch pedal 52tothereby engage clutch B will new result in the vehicle being driven forwardly in second or intermediate speed ratio and, as soon as the plunger I25 is returned to clutch engaged position, springs I2I and I22 act to thrust the valve stem II5 rearwardly to the position shown in Fig. 10 which actionconnects therear end of cylinder I04 with pressure port I56 through the intermediary of chamber II1, passage I5I and port II3, while at the same time the forward end of the cylinder is vented through port H2, passage I45 and chamber I I8 which is connected to the vent passage I44 through port I49. So long as the plunger I25 is in clutch engaged position, as illustrated n Fig. 10, there is no pressure on in the cylinder I04 because pressure port I53 is blanked off by the plunger I25. 1

After acceleration of the vehicle in intermediate speedratio to predetermined desired speed, shift to high or direct speed ratio is accomplished by power actuation in response to depression of clutch pedal 52 sufficiently to disengage clutch B and move rod I 34 rearwardly to the positionillustrated in Fig. 11. As soon as plunger I 25 is moved rearwardly sufficiently to establish communication between port I53 and passage I54 fluid under pressure flows through passage I55 and port I50 into chamber II1 and as this chamber is connected to the rear end of cylinder I04 piston I01 is immediately thrust forwardly to shift rail 82 and clutch sleeve 61 forwardly to clutch the teeth thereof with clutch teeth 68 thereupon establishing direct drive connection between shafts 55 and 65.

It will be noted that the forward stroke of the piston I01 takes place during release of the clutch, plunger I 20 under these circumstances locking the stem against movement which results in springs IZI, I22 being placed under compression through movement of the rod I I9 forwardly Release of the-clutch pedal will now cause the .ve-

hicle tobe driven forwardly in direct drive and 'Thus it will be seen that the next time that clutch pedal 52 is depressed, piston I 01 will be shifted rearwardly of cylinder I04 therebyto effect shift of clutch sleeve 01 back to second speed ratio position, no manual actuation of'the shift mechanism being necessary. a

It has been foundperfectlyfeasible with proper choice of gear and axleratios to start'thevehicle in second speed ratio; ,lowspeedratiobeingreserved for emergency starts and for negotiating .steep grades, sand, snow, etc. v.Eio long as the 3 driver wishes to drive the vehicle forwardly under inormal driving conditions shift of the .clutch ;sleeve 61 is entirely .automatic in response to v operation of clutch pedal '52. For example, when the vehicle is brought to a stop at atrafiic light, depression of clutch pedal 52 will result in the sleeve 61 being shifted rearwardly to second speed position preparatory to starting the vehicle in this speed ratio upon re-engagement of the clutch,

and as soon assufiicient speed has been obtained a depression of clutch pedal 52 will result in the sleeve 61 being shifted to high speed position, the

matically set for shift of the piston I! in the opposite direction upon subsequent depression of the clutch pedal.

It will be understood that the clutch pedal must i be depressed only sufficiently to establish com munication between port I53 and passage :54

during automatic operation of the transmission,

I full depression of the clutch pedal to the Fig. 8

position being made only when manual manipulation of the transmission is desired. The detent 1 I38 acts to maintain the collar I31 in inoperative position except when the clutch pedal is depressed to its full extent. For this reason it is preferable that the spring controlling detent I38 be made mechanism, the clutch pedal 52 being depressed fully to cut off communication between port I53 It may thus be seen that we have provided a simple and fool-proof power actuated mechanism which may be easily applied to a standard trans mission for shifting the same between second speed and high speed positions for normal forward driving. Our improved power shifting mechanism does not interfere with the ordinary 3 manual control of the transmission which may be resorted'to at any time, it being necessary only to depress. clutch pedal 52 sufficiently to move the collar I31 rearwardly to blank off the pressure port I53 when it is desired to shift either the gear BI or the clutch sleeve 61 manually.

action of the power mechanism being entirely,

1 automatic with the valve stem I I5 being auto- 1 and passage. I54 while the gear $64 is being shifted I into engagement with reverse idler gear I86 as will be readily understood.

While but one preferred embodiment of our Q invention has been illustrated for purposes of dis closure, it will be understood that various changes may be resorted to by those skilled in the .art without departing from the principles'of our invention. r

1'. In a motor vehicle having an engine, a clutch and a changespeed transmission; a pressure fluid actuatedmotor for controlling said transmission so as to cause the transmission to drive atone speed ratio in one position of the motor and to drive at another speed ratio in another position of the motor; a valve for controlling said motor including' leader and follower members so arranged that said leader member may be operated in advance of said follower member, operation of said follower member causing operation of whereby saidleader member is operated in resaid motor; means operably connecting said leader member with said motor ationof said clutch.

\ '8 said clutch whereby said follower member may be locked against operation incidentally to open 2. In a motor Vehicle having an engine, a clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure fluid actuated motor for shiftingsaid member includ ing, a reciprocable piston operatively connected to said member so as to cause the transmission to be in the low speed drive position in one position of the piston and to be in the high speed drive position in another position of the piston, a control valve for controlling said motor; means operably interconnecting said piston and said valve clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure fluid actuated motor for shifting said member includ ing, a reciprocable piston operatively connected to said member so as to cause the transmission to bein the low speed drive position in one position of the piston andto be in the high speed drive position in another position of the piston, a control Valve for controlling said motor; means operably interconnecting said piston and said valve whereby said valve is moved to high speed position in response to movement of said piston 7 locking said valve against movement.

4. In a motor vehicle having an engine, a

clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure'fiuid actuated motor for shifting said member includmg, a reciprocable piston operatively connected to said member so as to cause the transmission to be in the low speed drive position in one position of the piston and to bein'the high speed drive position in another position of the piston, a control valve for controlling said motor; means operably interconnectingsaid piston and said valve whereby said valve is moved to high speed position in response to movement of said piston to low speed position and to low speed position in response to movement of said piston to high speed position; said interconnecting means including a to be in the low speed drive position in one position of the piston and to be in the high speed drive position in another position of the piston, a control valve for controlling said motor; means operably interconnecting said piston and said valve whereby said valve is moved to high speed position in response to movement of said piston to low speed position and to low speed position in response to movement of said piston to high speed position;said interconnecting means ;including a lost motion connection operable to permit movement of said piston in advance of corresponding movement of said valve; and means connecting said control valve with said clutch operable to lock said control valve against movement when said clutch is released.

6. In a motor vehicle having an engine, a clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure fluid actuated motor for shifting said member includ- 10 and arranged such that it is closed when said clutch is engaged and open when said clutch is released; lock means operably associated with said control valve for locking the same against movement during movement of said piston, and

means for operating said lock means in response to release of said clutch.

8. In a motor vehicle having an engine, a clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure fluid actuated motor for shifting said member including, a reciprocable piston operatively connected to said member, a control valve for controlling said motor; means operabl interconnecting said piston and said valve whereby said valve is moved to high speed position in response to movement of said piston to low speed position and to low speed position in response to mo-vement of said piston to high speed position; a master valv for controlling admission of pressure fluid to said mg, a reciprocable piston operatively connected to said member, a control valve for controlling said motor; means operably interconnecting said piston and said valve whereby said valve is moved to high speed position in response to movement of said piston to low speed position and to low speed position in response to movement of said piston to high speed position; said interconnecting means includin a, yieldable member operable to permit movement of said piston in advance of corresponding movement of said control valve; a master valve operably connected pressure fluid to said control valve, said master valve being constructed and arranged such that it is closed when said, clutch is engaged and open when said clutch is released; and means interconnecting said valves for preventing movement of said control valve when said master valve is open.

7. In a motor vehicle having an engine, a clutch and a change speed transmission, a shift member in said transmission adapted to be shifted from neutral to a low speed drive position and to a high speed drive position; a pressure fluid actuated motor for shifting said member including, a reciprocable piston operatively connected to said member, a control valve for controlling said motor; means operably interconnecting said piston and said valve whereby said valve is moved to high speed position in response to movement of said piston to low speed position and to low speed position in response to movement of said piston to high speed position; said interconnecting means including a yieldable member operable to permit movement of said piston in advance of corresponding movement of said control valve; a

master valve operably connected with said clutchv for controlling admission of pressure fluid'to said control valve, said master valve being constructed control valve includin inlet and outlet ports and a plunger operably connected to said clutch for operation when said clutch is released to establish communication between said ports; a pedal for controlling said clutch and master valve, said pedal having a normal range of movement for releasing said clutch and opening said valv and a further range of movement overtravelling'said normal range and means operable inresponse to operation of said pedal in said overtravelling range for cutting off communication between said ports.

9. In the combination set forth in claim 8,

means adapted for operation by the master valve with said clutch for controlling admission of plunger when the same is moved to openposi tion for locking said control valve against movement.

10. In the combination set forth in claim 8, means adapted for operation by said pedal for locking said control valve against movement when said pedal is operated in both ranges of movement. g

11. In a motor vehicle having an engine, a clutch, a pedal for controlling said clutch and a change speed transmission, a shift rail in said transmission adapted for shifting from neutral to low and high speed driving positions respectively; a hydrauli motor for shifting said rail including a piston and a piston rod operably connected to said rail; a control valve-for controlling said motor including a movable valve member operatively connected with said piston rod and so arranged that movement of said piston to high speed position urges said valve member to low speed position and vice-versa; a master valve DAVID A. WALLACE. EDWARD 0. LEE. 

